1. Field of the Invention
The present invention relates to a lubricating structure of a transmission, and in particular, to a lubricating structure suitable for a toroidal type infinitely variable automatic transmission.
2. Description of the Related Art
A lubricating structure of a transmission of this type known in the art is described, for example in Japanese Patent Laid Open Publication Hei No.3-92655. This lubricating structure is applied to a toroidal type infinitely variable automatic transmission, and as shown in FIG. 5, this lubricating structure comprises an output gear c provided coaxially with a rotary shaft b of the toroidal transmission mechanism a and rotating as a unit with an output shaft q which transmits power of an output disks r, a first counter gear e rotating as a unit with a counter shaft d disposed in parallel with the rotary shaft b and engaged with the output gear c, a second counter gear f disposed spaced from the first counter gear e in an axial direction and rotating as a unit with the counter shaft d, a bearing g for rotatably supporting the counter shaft d at a first counter gear e side, a bearing h for rotatably supporting the counter shaft d at a second counter gear f side spaced from the first counter gear e, a driving gear i disposed above the second counter gear f and engaged with the second counter gear f through an intermediate gear (not shown), and a case n for individually accommodating through a separating wall m the bearing g, a bearing (not shown) for rotatably supporting a rotary shaft of the intermediate gear and a bearing k for rotatably supporting a rotary shaft j of the driving gear i, and a feed path o formed in an inside of the counter shaft d along an axis line and for supplying an oil introduced from an end portion at a second counter gear f side of the counter shaft d to each portion by leading to a first counter gear e side.
The feed path o is supplied with the oil by forced lubrication by an oil pump (not shown) from the end portion at the second counter gear f side of the counter shaft d through an oil path p formed in the case n.
However, in such a lubricating structure of the transmission, the forming of the oil path p through the case n is troublesome, and furthermore, there is a drawback in that because the oil pump is not driven while the vehicle is towed by another vehicle, it is impossible to feed oil to the feed path o, and thus to various portions.
Accordingly, in order to resolve such a drawback, a so-called raking or scraping lubricating system has been proposed in which the oil accumulated in a portion of the second counter gear f is raked or scraped by the rotation of the second counter gear f (which is rotated even under tow by another vehicle) to move the oil into a portion of the case n accommodating the bearing h, and then this oil which has moved into the accommodating portion is introduced into the feed path o from an opening at the end portion at the second counter gear f side of the counter shaft d.
Here, in the proposed raking lubricating system, it is desired to increase the amount of oil introduced into the feed path o and to supply sufficent oil to various portions. In particular, in the toroidal transmission mechanism as shown in FIG. 5, because the output gear c, the first counter gear e and the bearing g are disposed in a narrow space between the pair of output disks r having their rear portions opposing to each other, it is difficult to supply sufficient oil to these portions. Thus, it is desired to increase the amount of oil introduced into the feed path o in order to supply sufficent oil to the output gear c, the first counter gear e and the bearing g, etc.